Problem: Evaluate. $\left(-2\dfrac14\right)^2 = $
Answer: Let's start by converting the mixed number to a fraction. $\phantom{=}\left(-2\dfrac14\right)^2 $ $=\left(-\dfrac{9}{4}\right)^2$ $=-\dfrac{9}{4}\cdot\left(-\dfrac94\right)$ $=\dfrac{81}{16} $